dwightlooi

One thing they should really change but didn't was the steering wheel. The 3-spoke GM standard issue steering wheel is the ultimate expression of El Cheapo. The is the first thing which the driver grabs and which he stares at touches all the time, and this is where the G6, the Malibu and other GM products feel the cheapest. The Cruze wheel and the G8 wheel looks a lot better. This 3-spoke Rubbermaid special is no doubt on the way out, I am just a little disappointed they didn't get rid if it during the G6 refresh.

Oh... oh thing I forgot to mention... which is kind of important whether you are building a high reving engine or a torquey turbocharged one. Both the V6 and the V8 have -- all else being constant -- weaker bottom ends compared to a 4-potter. The reason is simple. A V6 typically has 4 main bearings and three journals. Two pistons and their connecting rods share one journal. A V8 has typically 5 main bearings and 4 journals, again two pistons and their rods share one journal. The Inline-4 has 5 main bearings and 4 journals, each piston and its rod has its own journal with main bearings to both sides. This yields a stronger bottom end. What does it mean? It means that it is easier to build a high specific torque or extremely high reving four without bottom end failures than it is to do the same with a V6 or V8.

That is not my impression when I drove the 2.0 LNF and the 3.6 LY7. The LNF is smooth and silky from idle to the redline (~6200). The 3.6 starts making mid frequency groans at about 5000 rpm and didn't sound like fine machinery for the last 1000 rpm of its rev range. At the low and mid rev ranges there is no difference in refinement, but the 2.0 LNF is more responsive and more alive when prodded. There are many instances where V6es are uninspiringly whereas 4-potters are superbly refined. The Mitsubishi 4G63 in the older Evos and the Eclipses of yore is wonderfully refined. The LNF is wonderfully refined. The VW/AUdi 2.0T is fantastic too. The Ford Duratec 2.5 and 3.0s, the recent GM 3.5 V6 and the Mitsubishi 3.8 V6 are all pretty rough and gritty. Worse than all of the aforementioned fours and jeez worse than even the big displacement fours like the Ford/Mazda 2.3, the GM 2.4, Honda 2.4 and the Toyota 2.4. Of course, there are horrible fours as well... the 2.4 SR24DE in the old 240SXes and Altimas come to mind as well as the 2.5 Iron Duke I4 in the Fiero and other GMs of the 80s. There are three factors which contribute to refinement of an engine (or the lack thereof). (1) Natural Vibrations (2) Power pulse density (3) Block stiffness An I4 is 1st order balanced, with up/down second order vibrations. These can be mostly canceled out by a pair of counter rotating balance shafts turning at twice the crank speed. The I4 has 2/3 the power pulse density of an 6-cylinder engine; the density at 3000 rpm is similar to that of a V6 at 2000 rpm for instance. Power pulse density related coarseness tends to be noticeable only at very low rpms, at even cruise speeds it disappears. Block stiffness limits the amount of flex in the engine block during operation. A stiff engine emits pleasing high frequency resonances (like a Ferrari or Porsche engine), a flexy block emits a low frequency sounds like a 90s 3800 V6. A V6 in the 60 degree configuration as mild 1st order vibrations. They are typically left alone because its deemed acceptable and there is no room in the Vee for a balancer. A 90 degree config as significantly worse 1st order vibs, and most 90 degree sixes have a single balancer turning at crank speed. An I6 is naturally balanced. The six cylinder engine has an advantage in pulse density at low rpms. A stiff block however can be tougher to achieve in a V6 and especially an I6 than in an I4.

Care to share "why"? Why does a 4-cylinder 300 hp engine that is smoother, lighter, more economical and has more torque down low than a 3.6 liter six suck? In fact, that is a 2.0 liter 4-pot mill with torque peaking at a lowly 2200 rpm, but which makes more power than the average Northstar V8. If you drive the 3.6 DOHC V6 in the Malibu and the 2.0 DI Turbo in the Solstice, the later comes off as smoother, torqueier, more "alive" and in general a tad more refined. Is it image? Well, the Audi A4 2.0T and the TT hasn't hurt the Audi image. So, again... why do you think it'll suck butt?

(1) I drew them. (2) They were drawn this way... Determine the torque curve* Plot the power curve based on the torque curve** KKK K04-0025 compressor map (LNF's current turbo) * If you look at the torque curve of a modern turbocharged engine, they have a steep ramp up on the left, a plateau and a somewhat steep fall off on the right. Estimating the slope and the position of the left and right slope is possible if you have the compressor and turbine maps of the turbo. Basically, the surge front --the left hand boundary -- of the compressor map and to a lesser extent the efficiency of the turbine will tell you roughly how quickly the turbo will spool. The right hand boundary of the compressor map will tell you roughly how much air you can move before the compressor becomes so inefficient that you are heating the air up as much as you are compressing it -- which is when more boost does not yield more power, just an equal or more amount of heat. If you simply plot the torque curve based on the maps, you'll get a curve that looks like the fin of a shark. This is the torque curve you'll make by letting the turbo make as much boost as it can make at all points, assuming that your fuel is knock proof and the volumetric efficiency is 100%. That's rubbish of course. So, you temper the curve down by the estimated volumetric efficiency of the engine at each rpm point (the original 260hp curve of the LNF tells us a lot about the VE of the engine at all points up to 260hp flow rates really). You also then decide on how much torque you want to limit the engine to -- in the LNX's case it's 270 lb-ft. You chop the top of the curve off based on that and you have your plateau. You then go back and see if everything makes sense. The forward slope in this case is a little to the right and a little less steep -- OK, typical of a turbo with slightly larger wheels and more inertial. Maximum torque arrives about 200 rpms later, peaking a very modest 10 lb-ft higher. The reverse slope however shows the advantages of modern aerodynamics and frictional benefits of the ball bearing cartridge of a turbocharger like the GT25R -- you don't fall off the map for another 700 rpms! Stretching the plateau out to 5900 rpm vs 5200 gets you the horsepower increase. ** The power curve is plotted simply as hp = torque x rpm x 5252. Not much to explain here, it's the definition of "horsepower".

The whole idea IS the four cylinder part. Everyone else has a six which comes with six cylinder mass, six cylinder economy and six cylinder commodifications. Instead, you drop in a turbo 4 that has just as much torque and power as a DI 3.6 V6, better economy and less weight up front. Traditionally, a turbo 4 making 300 horses (especially if its from 2 liters of swept volume) will be a frenetic, peaky, laggy and edgy powerplant. But we already know how to make it super civil and responsive, so we should capitalize on that and deliver a positive market differentiation. It's all fictional, but fully plausible. Let's leave it at that.

Like this... 2011 Cadilac RTS Vehicle Type: Compact Sedan / Coupe Base Price: $32,000 (Base); $45,000 (RTS-V) Standard: Power Windows, seats, locks; remote locking, cruise control, tilting/telescoping steering wheel, auto-dimming side and rear view mirrors, Piano Black trim, leather upholstery, BOSE 9-speaker sound system, HID headlights, On-Star, tire pressure sensors, variable assist power steering Options: Navigation, Bluetooth phone interface, Rear Parking sensors and camera, Rain sensing wipers (Luxury Collection); Sapele Wood Trim, Panoramic Moonroof (Elegance Collection); Suede Leather inserts, 18” Forged Aluminum wheels, Cross-Drilled brake rotors, FV5 sports suspension package, Helical Limited Slip Differential (Performance Collection); 3.6 liter twin-turbo engine, 19” forged alloy wheels, 6-piston Brembo front calipers, 4-piston Brembo rear calipers (RTS-V Edition); 6-speed manual transmission (Manual Edition) Curb Weight: 3335 lbs (Base); 3595 lbs (RTS-V) Wt. Distribution: Front:51%; Rear: 49% (base); Front: 53%; Rear: 47% (RTS-V) Wheel base: 108” Engine: Turbocharged and intercooled 2.0 liter Inline-4, aluminum block and heads (Base) Turbocharger(s): 1 x Honeywell-Garrett GT2560RSD, ball-bearing/dual scroll Bore x Stroke: 86 x 86 mm Displacement: 1998 cc Compression ratio: 9.2:1 Power (SAE net): 300 bhp @ 6000 rpm Torque (SAE net): 270 lb-ft @ 2200~5800 rpm Redline / Rev limiter: 6000 rpm / 6400 rpm Fuel Type: Premium Unleaded (91 octane) Turbocharged and intercooled 3.6 liter V-4, aluminum block and heads (RTS-V) Turbocharger(s): 2 x Honeywell-Garrett GT2252R, ball-bearing/single scroll Bore x Stroke: 94 x 85.6 mm Displacement: 3564 cc Compression ratio: 9.7:1 Power (SAE net): 468 bhp @ 5850 rpm Torque (SAE net): 423 lb-ft @ 2000~5800 rpm Redline / Rev limiter: 6000 rpm / 6400 rpm Fuel Type: Premium Unleaded (91 octane) Transmission: Hydramatic 6L50 6-speed automatic (Base) 1st 4.06 2nd 2.37 3rd 1.55 4th 1.16 5th 0.85 6th 0.67 Rev -3.20 Ratio Spread: 6.06 Maximum engine hp rating: 315 bhp Maximum Input Torque rating: 335 lb-ft Maximum shift speed rating: 7000 rpm Aisin AY6 6-speed manual (Base) 1st 4.155 2nd 2.513 3rd 1.691 4th 1.271 5th 1.000 6th 0.752 Rev -3.672 Ratio Spread: 5.525 Maximum engine hp rating: N/A Maximum Input Torque rating: 273 lb-ft Maximum shift speed rating: N/A Hydramatic 6L80 6-speed automatic (RTS-V) 1st 4.03 2nd 2.36 3rd 1.53 4th 1.15 5th 0.85 6th 0.67 Rev -3.06 Ratio Spread: 6.01 Maximum engine hp rating: 469 bhp Maximum Input Torque rating: 439 lb-ft Maximum shift speed rating: 6500 rpm Tremec TR6060 6-speed manual (RTS-V/Manual Edition) 1st 2.664 2nd 1.783 3rd 1.302 4th 1.000 5th 0.741 6th 0.502 Rev -2.903 Ratio Spread: 5.307 Maximum engine hp rating: N/A Maximum Input Torque rating: 470 lb-ft Maximum shift speed rating: N/A Wheels & Tires: Front: 17 x 7.5” cast alloy; Rear 17 x 9” cast alloy (Base) Front: 225/45 ZR17 Goodyear Eagle GT Rear: 255/40 ZR17 Goodyear Eagle GT Front: 18 x 8” cast alloy; Rear 18 x 9.5” cast alloy (Performance/Optional) Front: 225/40 ZR18 Goodyear Eagle F1 Asymmetric Rear: 265/35 ZR18 Goodyear Eagle F1 Asymmetric Front: 19 x 8.5” forged alloy; Rear 19 x 10.5” forged alloy (RTS-V) Front: 245/35 ZR19 Michelin Pilot Sport PS2 Rear: 295/30 ZR19 Michelin Pilot Sport PS2 Brakes: Front: 12.4 x 1.2” vented disc w/4-piston Brembo Fixed Calipers (Base) Rear: 11.3 x 1.1” vented disc w/2-piston Fixed Calipers Front: 14.6 x 1.3” slotted & vented disc w/6-piston Brembo Calipers (RTS-V) Rear: 14.4 x 1.1” slotted & vented disc w/4-piston Brembo Calipers Performance: 0-60 mph: 4.8 secs (Base/Automatic) 0-60 mph: 3.9 secs (RTS-V)

(1) A 2 liter DI turbodiesel with around 170hp can be used for the European fuel misers. But the idea is to build the car around one engine not 5 different ones. (2) The idea is not to make as much power as possible from the 2.0 liter engine. The idea is to make the maximum amount of virtually lag free and immaculately civil horsepower -- a car competing in the luxury compact segment needs that more than it needs to shave 0.5 seconds off its quarter mile time. They have already done this at 260hp, now do the same at 300. (3) ~3300 pounds is doable for a car this size with today's crash safety, chassis rigidity and interior furnishing expectations. (4) For a RTS-V you can indeed stuff a 3.6 DI V6 Turbo in there. But 400~420hp is a bit modest. With two GT2259 class turbos and a relatively conservative 14.7 psi the output should be pegged at the limit of the 6L80 transmission say around 468hp @ 5850 / 423 lb-ft @ 1800-5800. We are talking about the same amount of specific power output as the current 260 hp LNF with less specific torque output. Again, using an air-to-water IC we can eliminate the large amounts of pressurized volume in the typical dual intercoolers and their associated plumbing.

The formula for beating the BMW 3-series may be real simple. Here goes:- (1) RWD- Alpha platform (~108" wheelbase, ~3300 lbs, 5 seats, 4-doors, styled like the Torana; sized between the 3-series and the IS) (2) Finish the Interior to the same standard as the CTS - not quite Audi, but good enough to combat BMW interiors (3) Keep it 4-cylinders only -- a 300hp / 270 lb-ft version of the 2.0 liter LNF engine. (4) Give it the excellent 6L50 tranny. (5) Keep it around $32,000 to start. That's it. You have just stuffed the 328 and matched the 335 in performance and beat them both in terms of not just price but also fuel economy with an EPA rating estimated to be around 22/28. As far as the engine is concerned, the technology and techniques to make a 300hp 2-liter engine silky, civilized and quiet is already here. 40 hp more from the LNF seems like a lot considering the already overachieving nature of the 260hp 2 liter turbo. But it really isn't. Here's how... The LNF currently makes 260 hp and 260 lb-ft. It is practically lag free and it is in many ways more civilized than the 3.6 V6. The turbo spools fast and early, but starts to run out of steam after about 5250 rpm when hp peaks. If we simply extended the 260 lb-ft torque plateau from 5250 rpm to 5850 rpm we get 289 hp. Bring it up to 270 lb-ft and you get 300hp. This is exactly the estimated net output at the SAME boost level if we substituted the KKK K04 turbo's compressor and turbine maps with that of a Garrett GT2560 turbo's. Yes, the wheels are bigger and inertial may be higher. But the ball bearing cartridge and the retention of the dual scroll housing will counteract the loss of responsiveness. About 270 lb-ft of torque should arrive at around 2000~2200 rpm regardless. If you really want to make this the best 4-potter turbo engine bar none (snuffing the Lancer Evo, Mazdaspeed and WRX STi's powerplants), the path is also paved and ready to tread. It's simple, you drastically reduce the pressurized volume which is just as responsible for turbo lag as the sizing of the turbo. The turbo has to bring the long hoses and the big front mounted intercooler to 18 psi before the engine sees 18 psi. That takes a little time. Get rid of it all and response becomes lightning sharp. GM already has the experience with air-water intercoolers -- having used them in the LSA and LS9 engines. With an air-water system you simply route the turbo's output through a short solid pipe to the intake side to feed an intake manifold with a small, integrated, air-to-water intercooler brick ala LSA. This minimizes the pressurized volume and maximizes engine response. The water lines and the size of the IC-radiator will not hamper engine response because they are not part of the pressurized air volume..

GM Electra – Performance Hybrid Module The Electra module is a hybrid drive train system that can be added to existing GM RWD drive trains. It consists of a drop in rear differential replacement which includes a pair of highly compact 30hp permanent magnet motor/generators and a 1.5 kWh Lithium-Ion battery pack which fits in place of the spare tire well. More than just fuel economy While “green” buyers and individuals who subscribe to the global warming hypothesis may find buying a hybrid a worthwhile investment, anyone who does the math can see that at $4 a gallon it’ll take an average driver 6 to 12 years to just break even on an investment in a hybrid drive train. However, even a performance enthusiast who does not give an iota about fuel economy should consider the Electra package because it is designed, first and foremost, to improve the handling and performance of the car, with a healthy dose of fuel economy benefits being incidental to that. The Electra differential is actually a pretty simple device – a traditional open differential with one 30hp coaxial electric motor coupled to each of the output half-shafts. In straight line acceleration, up to 60hp can be metered to help accelerate the vehicle and during braking up to about 40kW can be recovered in regenerative differential braking. But more importantly the Electra differential transforms to the differential into an active device with the ability to add or subtract up to 30 hp from each of the two driving wheels. This is used to smoothly and continuously reign in under or over steer to significantly improve handling in a manner which ABS based stability control systems cannot. And, because the system can be additive instead of merely subtractive or biasing like purely mechanical systems it actually adds performance instead of dampening it when it does its work. Any motor, any vehicle, at a reasonable price The Electra package is designed to be applicable to just about any GM RWD vehicle without significant modifications. Initially it will be offered with the Pontiac Solstice, Pontiac G8 and the Cadillac CTS. But it can theoretically be used on RWD truck and SUV models as well. The package costs about $4000 at a retail level about on par with the hybrid packages available on the Camry or Altima. On the Solstice is mated to 240hp version of the highly acclaimed 2.0 liter DI turbo engine (LNF) which is modified to use lower boost (13.3 psi vs 18 psi) and higher static compression (10.2:1 vs 9.2:1) for better cruising economy. The Solstice Electra is also the first Solstice model to receive the 6L50E 6-speed automatic transmission giving it a 1 cog advantage over the 5L40E 5-speed unit in the GXP. The Solstice Electra produces a total of 300hp can out accelerates the conventionally powered GXP model to 60mph by 0.3 seconds and more importantly it out handles the GXP with sharper turn-ins, superior stability and greater exit speeds out of apexes. On the CTS Electra and G8 Electra the system is mated to a 292hp version of the 3.6 liter DI V6 engine with cylinder deactivation. Again, the transmission of choice is the 6L50E 6-speed automatic. A total of 348 hp is available and, likewise, handling is improved through the active power application and subtraction functionality of the Electra differential system. In either system, utilizing the differential’s handling enhancement capability does not deplete the battery tangibly because 90% of the power added to one half-shaft can be generated through regeneratively braking the other. -- This is a work of fiction, no such product or plan is known to exist or is implied to exist.

There is nothing wrong with FWD, fuel economy focused vehicles*. What's wrong is selling the same basic thing under several different brands. IMHO, if two brands are selling the same thing then there is no need for two brands! I am sick of this brand engineering BS already. If GM doesn't want a full line, performance and driving experience focused brand then it should get rid of Pontiac or reduce it to a maker of the Solstice and other niche vehicle models. Otherwise, GM should do its darnest to give it a product line that is as different from Chevy's as possible. It doesn't make sense to make a Pontiac and Chevy version of the Cruze and the Malibu. Pontiac doesn't have to have its own version of everything Chevy, in fact the whole point should be that it DOESN'T. If it does, then all you'll be doing is splitting the pie between the two brands; you won't be baking a bigger pie! I think the future Pontiac line up should be:- Mainstream: G4 -> Alpha Kurz Platform Coupe (Compact RWD w/2.0 liter DI VVT NA, Turbo or HO Turbo engine (170~310hp) ~ 2900 lbs G6 -> Alpha Platform Sedan (Compact RWD) w/2.0 liter DI VVT NA, Turbo or HO Turbo engine (170~310hp) ~ 3200 lbs G8 -> Zeta Platform (Mid-size RWD) w/3.6 liter DI VVT or 6.2 liter OHV engines (300~432hp) ~3700 lbs Solstice -> Kappa Platform (Compact RWD - coupe/roadster) w/ 2.0 liter DI VVT NA or Turbo engine (170~260hp) ~2900 lbs Performance Hybrids**: E4 -> Alpha Kurz Platform Coupe (Compact RWD w/2.0 liter DI VVT Turbo engine + 60hp electric assist (260+60hp) ~ 3200 lbs E6 -> Alpha Platform Sedan (Compact RWD) w/2.0 liter DI VVT Turbo engine + 60hp electric assist (260+60hp) ~ 3500 lbs E8 -> Zeta Platform (Mid-size RWD) w/2.0 liter DI VVT Turbo engine + 60hp electric assist (260 + 60hp) ~4000 lbs Solstice Electra -> Kappa Platform (Compact RWD - coupe/roadster) w/2.0 liter DI VVT Turbo engine + 60hp electric assist (260 + 60hp) ~3200 lbs Cancelled -> All Pontiac SUVs, Vibe (crossover) *Technical Side Note: Who says that fuel efficiency and RWD are mutually exclusive? Really it comes down to drive train loss and an addition 100 lbs or so of platform weight on a 3000 lbs class vehicle. Typical RWD drive train loss is ~ 15% whereas FWD is ~10%, a 5% difference. In terms of MPG, you are looking at a similar 5% reduction such at a 22/30mpg vehicle will then become about 21/28.5mpg -- really does that matter that much? You can make more of a difference switching tire types and/or inflation pressures than switching from RWD to FWD! The 100 lbs increase probably doesn't even register on the fuel economy sticker -- it's like the difference between driving with a full 16 gallon tank and a near empty one with 1 gallon of fuel left in it (15 gallons = 57 liters = 45.6 kg = 100.4 lbs! **Technical Side Note: All Hybrid Pontiac models should use the same hybrid add-on for developmental expedience and economy. This includes a Li-Ion battery pack replacing the spare tire well and a 60hp (45kW) permanent-magnet rear-differential-motor-generator (RDMG). This is actually two separtate 30hp motors coupled to the left and right differential output shafts. The entire system should weigh in at a 300 lbs mass delta. One side benefit of the hybrids can be "Regenerative Active Handling". Because the motors are independently coupled to the left and right outputs, and are by nature capable of functioning as motors or generators, the computer can electronically add or remove up to 30hp from both the inside or outside rear wheel during hard cornering. This can be used to automatically correct for understeer or oversteer using differential electric motor input or power draw. In fact, if properly managed the use of active handling won't even deplete the battery pack because the power used by the motor on one side is actually generated by the motor on the otherside (minus the 10% or so generation/induction loss)!

OK... one good thing I am seeing is that the Cruze does not appear to be a flat floor design. It looks like it has a center hump... which is good. It means that technically it should be possible to stick a drive shaft in there and a differential in the back. Throw in the 2.0 DI Turbo (LNF) or a derivative, add an intercooler mister and all of a sudden the General has a WRC Special.

That's actually relatively cool. Better than looking like GM product planners flunked out of grammar school and can't even spell Cruise.

Honestly, Cruze REALLY sucks. Even Cobalt is better than Cruze. I'll rather stay in the periodic table and pick another metal or something. Nicer elemental names include:- At (85) - Astatine Os (76) - Osmium Pm (61) - Promethium Ir (77) - Iridium Xe (54) - Xenon Y (39) - Yttrium Of these... I think Chevy Iridium sound the best.

The Cruze is a nice enough car. Unlike some others I think the styling is nice and clean for the most parts and the interior is a huge leap forward for Chevy. I have some reservations about a 1.4T being more economical than a 1.8 DI, but at least it serves to differentiate the car from the flock. However, there is nothing to like about the lame name that sounds like "Curse" or (Tom) "Cruise". So, I am proposing that we come up with some alternative names for this bread and butter Chevy of the future. I propose that Chevy name all their mainstream vehicles after places or cities. There is already some sort of a tradition in that direction -- Malibu, Tahoe, Colorado, etc. Naming vehicles after American cities makes them sound American and this is also an unpretentious, unsnobbish way of naming products. For a compact car designed for fuel economy and with a focus on urban driving in mind, why not Chevy Manhattan?

One thing of note: None of the GM releases indicate that the "Family Zero" engines -- including the 1.4 liter Turbo -- features direct injection. Some magazines and various forum posters have made that assumption, but I haven't seen anything official on it yet.

The gas turbine has a few problems... (1) A simple cycle gas turbine is less efficient than a piston gasoline engine and much less efficient than a diesel engine. The main reason is that a lot of the energy made by burning the air and fuel is simply dumped out the tail pipe as very hot exhaust gases. The single or dual stage exhaust turbine simply cannot harness as much of the combustion energy to do work as a a piston in an enclosed cylinder. (2) When you are using it to mechanically drive the wheels, you introduce two huge problems. The first is that the turbine takes about 5 seconds to go from idle to full power, that's like turbolag times 10. Basically, the engine respond to your throttle input with huge multi-second delays which makes the car undriveable on public roads. The second being that the engine can be horribly inefficient and sometimes smoky when operating outside it's ideal operating rpm. Imagine an regular engine that drinks gas horrendously or spews black smoke if you don't keep it at between 4000 and 4500 rpm -- that's unacceptable to anyone. However, none of these problems remain in a COGES drivetrain. The wasted energy in the exhaust is recaptured to boil water and drive a closed cycle steam turbine. The total thermal effciency of a COGES plant can approach 60% which is better than even diesel engines. Turbine lag and inefficiencies at other than ideal speeds are also retired when you run the turbine for no other purpose than to turn an electric generator. The turbine does not turn faster or slower regardless of how you accelerate or decelerate. It turns at a steady, optimum speed to recharge the batteries, the batteries and the electric motor coupe with changing driver requests for power.

(1) I do not believe in the Global Warming hogwash, but that is another topic for another time. (2) As a symbol of technological superiority, I think GM hasn't gone far enough with the Volt. They should have dumped the big, heavy and only moderately efficient piston engine for a combined cycle turbine generator set. Each turbine will have only one moving part (or two if its an advanced dual shaft design), each will be the size of a stack of 100 DVDs. There will be no coolant, no radiator, no water pump, no camshafts, no timing chains, no valves, no springs, no rods, no crank, no connecting rods, no balancer shafts, none of those things that fill up the engine bay, add weight and restrict packaging by having to be clustered together. A turbine generator can easily fit in the spare tire well even divided up and stuffed into fender spaces here and there.

The last time I was in Aussieland, the Euro Accord seems to be everywhere... that is a 2.4 liter K24 powered mid-size. I don't think there is a problem with a 4-pot Commodore especially when there is also a V-6 version available for the doubters. Having said that, I think one test drive will changen the minds of most. I have driven both the 3.6 liter V6 (in a Saturn Aura) and the 2.0 LNF in a (HHR SS) -- both both FWD. I can tell you that the 2.0 liter LNF is feels more powerful and sounds more refined especially when wound out past 5000 rpm. The 3.6 is dutiful and unobjectionable, the 2.0 sings a beautiful song accompanied by a muted but unmistakable whistle from the turbocharger. Just the numbers though the LNF wins... 3.6 liter VVT (Port Injected) --> 252hp @ 6300 rpm, 251lb-ft @ 3200 rpm 2.0 liter LNF (DI Turbo) --> 260 hp @ 5250 rpm, 260lb-ft @ 2000~5250 rpm

Nah... the 1.4 can be the base engine and anyone who wants a hot compact can have an optional SS with the 260hp 2.0 liter LNF.

Well, the truth is it's too early to peg the horsepower rating. A 1.4 liter engine with a turbocharger can safely and reliably make up to 210 hp. However, in a car targeting the average buyer with a nod towards fuel frugality power may not be the leading concern. This brings into light various concerns such as the ability to use 87 octane fuel and turbo lag. Also, depending on your driving style a more responsive engine with a 10~20 lb-ft less torque, but with a torque peak in the 1000s range may feel more powerful than one with more torque peaking higher up in the rev range. I know... I am married to a lady who probably has never broken the 3500rpm mark on her Civic's tach and probably never used more than 20~30% throttle on that 1.7 liter 115hp engine! With direct injection and variable cam phasing making about 130hp/liter will mean a little lag running to about 18 psi of boost, torque peaking at 2000~2500 rpms and a diet of 91+ Octane. Going to 100hp/liter will get the torque peak down to 1600~2000 rpm with a practically zero lag ~9 psi and will likely open the door to 87 octane specification. If you want to incorporate stratified charge operation (aka lean burn), then power goes down even more due to special intake runner geometry and nitrogen storing catalysts which are not exactly consistent with the flow maximizing profile of an engine tuned for performance. Even though I am not convinced that a 1.4 liter DI-Turbo will be any lighter or more economical than a 1.8 liter DI NA engine, the good thing about a turbocharged engine is that dialing up another 30 hp from the 1.4 liter turbo is really just a software change away. So... GM can have a super economical tune at 120hp but add a switch on the dash board. Push it and you get another 40 hp with premium lose a few MPGs in the city. The main difference is probably the electronic boost control map and using a fuel enrichment as an anti-detonant -- going from about 7 psi to about 15 psi and running richer mixtures than optimal.

A C-VVL system like this can work on a cam-in-block engine like the LS3 or L99... by basically changing the rocker ratio from say 1.3:1 to 1.73:1 continuously...

It's a nice looking car. Very modern, very proportionally "right". Sleek roof line, short hood, high deck. Just as unique but far better looking than the Camaro or the Cruze. I like it! Hybrid or not, Chevys should look like that. Maybe they should have a high performance version of it... say a two 120kW (240kW; 321hp total) Permanent Magnet motors driving the wheels. Forget the plug-in part and just have a low capacity, high current Li-Ion battery to cope with short acceleration bursts. Power can come from a 60~70kW gas turbine generator the size of a small waste paper basket. Again, performance, light weight and high power density is the goal here not ultimate fuel economy. It'll be RWD, it'll have the equivalent of active differentials with its ability to meter torque to the left and right rear wheels at will, it'll be light given the extremely small gas turbine generator plant.

The styling a little plain, but that is not necessarily a bad thing. At least it isn't blatantly ugly like some GM designs of the past -- the Grand Am, Monte Carlo, Firebird, Corvette Stingray, 82-92 Camaro, Saturn S-series, Aurora, etc comes to mind. And, it doesn't have dubious tack on features that spoils an otherwise petty cars -- like the nostrils intakes on hood of the G8 or the fake vents on the Saturn Sky. The Cruze isn't as distinctively its own stlying wise like the Civic, but neither are any of the other cars in the segment. In this segment, that is not particularly important. What is important is that the car be technologically up to date in the eyes of the buyers, offer good economy and is reliable in service. And it looks like it will with the 6-spd auto and a 1.4 liter DI-turbo powerplant. If the interior can be anything like a Volkswagen which they are benchmarking it should be pretty good. Tack onto that a youthful image and perhaps an image bolstering SS model and it should do just fine.

The 2.0 Liter LNF is a nice little engine in turbocharged form. But as a base engine on a small car like the upcoming Cruze it may not exactly be the right prescription. However, the 2.0 liter block can form the basis of a nice little engine designed for economy instead of performance. And one of the ways we can optimize it for gas sipping duty is to incorporate Part-Time Atkinson Cycle operation using cam switching hardware already tested on the HCCI concept 2.2 engines. Since the engine block and most components are shared with the LNF it also reduces costs and inventory if the vehicle will also have a turbocharged high performance stable mate. Atkinson Cycle (and its supercharged Miller Cycle variant for that matter) operates on a principal that an asymmetric intake and exhaust stroke extracts the best thermal efficiency out of a piston engine. The physical piston stroke is no different from a regular engine. However, the intake valves on an Atkinson Cycle powerplant does not close until the piston is well into its compression stroke. This causes part of the intake charge to be kicked back out of the cylinder during the compression stroke and there is also no effective compression for the portion of the compression stroke where the intake valves remain open. For instance, if you have a 86 mm physical stroke, but keeps the intake valves open for 30mm of that stroke, you have in essence created an engine with a 56mm compression stroke and effective dispacement, but a 86 mm power stroke. This helps extract more energy by simply allowing the pressurized gases more time and distance to do their work before venting them. The downside is that the "effective displacement" of the engine and hence its power output is similar to that of an engine roughly 2/3rds the physical size. The plus side is that the efficiency is often times better than an engine 2/3rds the size. Example: The Prius's 70hp 1.5 liter engine is the Atkinson Cycle version of the 108 hp 1.5 liter 1NZ-FE engine in the Yaris/Vitz/Echo. However, all the aforementioned downsides of an Atkinson Cycle engine assumes that the engine is always operating in Atkinson cycle mode. With cam switching technology (ala VTEC, VVTL-i, MIVEC and whatever GM's implementation ends up being called) we can switch between two camshaft lobes. We can operate in Atkinson cycle or a conventional Otto Cycle at will by changing between a cam lobe which closes the intake valves very late and one which doesn't. This will create an engine which can switch to a cruising or light load mode with better economy than a typical 1.4 iter engine, and one which restores the performance potential of a 2.0 liter direct injection powerplant. The output will probably by around 160~170 hp in Normal Mode and about 100 hp in Atkinson Mode. Not bad really, for a small car. BTW, the Civic's 1.8 liter 140hp four is already pulling a similar trick.